1 Keys.Any()
写法类似于Linq。
Dictionary<string, string> dict = new Dictionary<string, string>();
string key="a";
if(dict.Keys.Any((e)=>string.Compare(e,key)==0)==false){
dict[key]="1";
}
2 TryGetValue()
Dictionary<string, string> dict = new Dictionary<string, string>();
string key="a";
string value="";
if(dict.TryGetValue(key,out value)==false){
dict[key]="1";
}
3 ContainsKey()
Dictionary<string, string> dict = new Dictionary<string, string>();
string key="a";
string value="";
if(dict.ContainsKey(key)==false){
dict[key]="1";
}
本人推荐第三种,这个简单一点。